1. Field of the invention
The present invention relates to a device for varying the alignment of wheels, particularly for in-line skates.
2. Description of the Prior Art
Conventional in-line skates are constituted by a shoe associated with a usually U-shaped frame. A plurality of wheels are pivoted between the wings of the frame and are thus mutually aligned.
A problem in the use of these skates is that it is not easy to achieve a quick change in direction owing to the parallel arrangement of all the wheels, with respect to the ground, the wheels may be as many as four or five.
This problem becomes evident in the user's need to have two structurally different skates: for slalom or for speed skating.
U.S. Pat. No. 2,412,290 offers a partial solution to this drawback and discloses a skate having a frame with three aligned wheels; the intermediate wheel is vertically adjustable to facilitate the maneuverability of the skate.
However, this solution is structurally complicated, because the vertical adjustment of the intermediate wheel can be achieved by means of a fixing bolt and a system of meshing teeth to produce the desired vertical adjustment.
U.S. Pat. No. 3,287,023 discloses a roller skate wherein, at the front and at the rear parts of the frame, there are seats at different heights for the arrangement of the rear and front wheels, which can thus be raised from the ground to varying extents.
Even this solution, however, is not optimum, because in order to vary the arrangement of the wheels it is necessary to disconnect them from the frame and reposition them in the desired point.
This entails long execution times and the possibility that the operator may lose a component if he first disassembles the wheels and then reassembles them.
U.S. Pat. No. 5,048,848 discloses a roller skate with aligned wheels that has bushes for axial openings for simplified installation. Slots are in fact formed on the wings of the frame of the skate so that the axis of the slots is at right angles to the ground. Bushes provided with eccentric holes can be temporarily placed within these slots; the arrangement of these bushes in positions, which are 180.degree. with respect to each other, inside these openings allows to place the pivot of the central wheels at a slightly lower level than the front and rear wheels, so as to improve curving.
Even this solution, however, is not free from drawbacks: first of all, in order to vary the elevation of the central wheels it is necessary for each wheel, to disengage the two bushes from the respective openings, rotate them, place them back in the openings, reposition the wheel in its place, reinsert the pivot, and lock it.
If the user then wishes to vary the elevation of the two central wheels, he has to perform several operations requiring a long time and with the possibility of losing bushes, bolts, and pivots during these operations.